In both periodontics and endodontics, effective irrigation of tissue and surrounding structures makes effective cleaning and disinfection possible. Irrigation is accomplished by agitating fluid. In periodontic procedures, such as gum surgery and in endodontic procedures, such as root canals, this agitation and irrigation eradicates bacteria and lessens the chance of infection. Agitating fluid causes disturbances, i.e., vibrations, that force out debris and other foreign particles that could irritate the area and lead to infection. By creating disturbances in saliva and fluids already in the cavities and/or cleansing chemicals that are added, such as hydrogen peroxide, the foreign particles and debris can be forced out of sensitive areas. For example, effective endodontic treatment requires the combination of physical and chemical agents to eradicate soft-tissue debris, smear layer, and microorganisms. In root canals, antimicrobial irrigants are commonly used.
Different agitation techniques have been proposed to improve the efficacy of irrigation solutions, including agitation with hand files, gutta-percha cones, plastic instruments, and sonic and ultrasonic devices. Photon-initiated photoacoustic streaming (PIPS®) refers to the use of a laser as a pulsing light source to create the agitation to irrigate areas in both endodontic and periodontic procedures. Acoustic streaming is a steady current in a fluid driven by the absorption of high amplitude acoustic oscillations. Photo acoustic streaming utilizes photons to induce oscillations.
PIPS® utilizes an erbium YAG laser, Er:YAG laser, (erbium-doped yttrium aluminum garnet laser) to activate irrigation solutions by the transfer of pulsed energy to agitate fluid and increase the efficacy or irrigation. This method has produced mixed results. Although some positive results have emerged as far as the elimination of bacteria, the use of Er:YAG lasers present a number of challenges including both cost and efficacy. For example, in an Er:YAG laser, the unidirectional emission of the laser beam makes it difficult to access the entire root canal wall with the Er:YAG laser. Additionally, a given Er:YAG laser can only project one wavelength and different dental procedures may benefit from using different wavelengths, and more than one wavelength at a given time. Due to the challenges presented by Er:YAG lasers, the capacity of PIPS® to disinfect root canals, and other sites that would benefit from irrigation, has not been established. Also, using an Er:YAG laser for this application may be cost-prohibitive for many dental practitioners.
Another challenge of using a laser, or any light source, in an irrigation solution is the potential for creating hot spots in the solution, and therefore in the mouth of a patient, which can lead to tooth and gum damage. When the light leaving the irrigation device and comes into contact with liquid in the mouth, such as a solvent, or water, the heat generated can converge in solution, creating a hot spot. This hot spot can cause pain as well as damage dental structures.
Unlike in endodontic applications, Laser Assisted Periodontal Therapy (LAPT) has been used effectively to battle periodontal disease. However, the wavelengths, pulse rates, and power settings utilized in periodontal treatments are presently incompatible with those attempted in endodontic applications.
Periodontal disease is a chronic inflammatory disease caused by bacterial infection. The inflammation is the body's response to destroy, dilute or wall off the injurious agent. Unfortunately, this response destroys the tissue. The periodontal pocket, in periodontal disease, contains several substances that contribute to the continuation of the unhealthy condition: calculus and plaque on the tooth surface, pathogenic bacteria, and/or an ulcerated, epithelial lining with granulation tissue and bacterial by-products.
Treatments for periodontal disease include scaling and root planing (SRP), which eliminates calculus, plaque and other debris on the tooth to create a totally clean surface, decontamination, which eliminated all pathogenic bacteria dispersed through the pocket, curettage, which eliminates granulation tissue, bacterial products, and ulcerated areas to create a clean, even epithelial lining without tissue tags, and biostimulation.
Laser sulcular debridement is used as an adjunct therapy to conventional root planing and scaling. The purpose is to remove the diseased epithelium of the periodontal pocket, leaving the healthy tissue intact. The diode laser is effective in treating diseased soft tissue. The diode laser energy is well absorbed by melanin, hemoglobin and other chromophores that are present in periodontal disease. By adding use of photo acoustic streaming with a laser diode as a light source, to SRP, the results in periodontal treatments have been significantly improved.
LAPT presents at least the following advantages over traditional surgical SRP: longer lasting results, decreased gingival bleeding, decreased inflammation, improved pocket depth, decreased tooth mobility and clinical attachment loss. LAPT can also reduce or eliminate the need for antibiotic post SRP or surgical treatments. In LAPT, there are no adverse effects to tissue, roots of the tooth, or cementum due to thermal side effects or the light beam itself.
This therapy utilizes the light energy emitted by the laser elicits beneficial cellular and biological responses. This therapy is effective on a cellular and a bactericidal level. On a cellular level, metabolism is increased, stimulating the production of ATP (adenosine triphosphate), increasing the energy available to normalize cell function and promote tissue healing. On the bactericidal level, the laser energy reduce and/or eliminates the bacteria of the periodontal pocket, including the sulcular wall, as much as possible and to form a stable clot.
A need exists for a system and method for photon-induced acoustic streaming for both endodontic and periodontic dental applications that is effective, affordable, and safe.